03 February 2014

The Impact of Age on Prospect Success Rates

In previous posts, I’ve written about Baseball America’s
success rates predicting which prospects will succeed in the majors. In this
post, I want to write about their success rates when taking age into account
from 1990-2006.

In order to determine how successful Baseball America has
been at predicting success of prospects based on age, I downloaded all the data
for all rookies who had a season of at least 100 PAs or 25 innings in the
majors and split them into groups based on whether they
were a ranked Baseball America Top Hundred prospect, whether they were a
position or pitching player and based on their age when they first entered the
majors. The age groupings are 20-22, 23, 24 and 25+. There were
very few players that made it to the majors before 20 and all of them were
ranked so I didn’t include them in this analysis.

As in previous posts, a successful prospect is one that is
worth at least 1.5 WAR per year for his first six years.If a player doesn’t have at least 100 PAs or
25 innings in the majors his first year than that year is omitted from the
calculations (but is still considered the year he enters the majors). If a
player doesn’t have at least 100 PAs or 25 innings in either of his first two
years than both of those years are omitted from the calculations. His third
year is included regardless of whether he has at least 100 PAs or 25 innings.

The first prospects I looked at were position prospects
ranked by Baseball America. The following table shows their success rates.

Age Group

Year Group

Success Percent

Number of Successful Prospects

20-22

1990-1993

42.59%

23

20-22

1994-1997

48.89%

22

20-22

1998-2002

31.03%

18

20-22

2003-2006

56.52%

26

23

1990-1993

39.39%

13

23

1994-1997

33.33%

5

23

1998-2002

44.44%

12

23

2003-2006

33.33%

9

24

1990-1993

43.75%

7

24

1994-1997

7.69%

1

24

1998-2002

20.69%

6

24

2003-2006

38.46%

5

25+

1990-1993

16.67%

1

25+

1994-1997

18.18%

2

25+

1998-2002

40.00%

4

25+

2003-2006

11.11%

1

The majority of successful offensive
rookies ranked by Baseball America are between ages 20-22 when they first play
in the majors and have the best success rates. Offensive prospects that don’t make it to the majors until they
are 23 or 24 still have high success rates.Offensive players ranked by Baseball America that do not make it to the
majors by 24 have lower success rates.

The following table looks at unranked offensive prospects
and their success rates:

Age Group

Year Group

Success Rate

Number of Successful Prospects

20-22

1990-1993

3.70%

1

20-22

1994-1997

13.04%

3

20-22

1998-2002

17.86%

5

20-22

2003-2006

19.35%

6

23

1990-1993

13.16%

5

23

1994-1997

5.56%

2

23

1998-2002

7.14%

3

23

2003-2006

11.11%

3

24

1990-1993

6.67%

4

24

1994-1997

13.33%

6

24

1998-2002

12.24%

6

24

2003-2006

15.56%

7

25+

1990-1993

4.72%

6

25+

1994-1997

3.95%

3

25+

1998-2002

6.90%

8

25+

2003-2006

6.25%

6

The number of successful prospects remains similar by age
but the chance of an unranked prospect succeeding decreases as he becomes
older. It is far less likely that an unranked offensive prospect will succeed
than a ranked one.Unranked prospects
that make it to the majors by 22 have a surprisingly high chance at being successful.

The following tables show the number of successful hitting
prospects by rankings.

Age

Year

1-10

11-20

21-30

31-50

51-100

Not Ranked

20-22

1990-1993

9

7

1

2

4

1

20-22

1994-1997

6

6

3

4

3

3

20-22

1998-2002

7

2

1

6

2

5

20-22

2003-2006

6

7

3

5

5

6

23

1990-1993

2

2

1

6

2

5

23

1994-1997

1

2

0

0

2

2

23

1998-2002

1

3

1

4

3

3

23

2003-2006

3

0

1

2

3

3

24

1990-1993

2

0

1

2

2

4

24

1994-1997

0

0

0

0

1

6

24

1998-2002

0

0

0

1

5

6

24

2003-2006

0

0

1

0

4

7

25+

1990-1993

0

0

0

0

1

6

25+

1994-1997

0

0

0

0

2

3

25+

1998-2002

1

0

1

1

1

8

25+

2003-2006

1

0

0

0

0

6

Age Group

Year Group

Not Top Hundred

Top Hundred

Success Rate

20-22

1990-1993

1

23

95.83%

20-22

1994-1997

3

22

88.00%

20-22

1998-2002

5

18

78.26%

20-22

2003-2006

6

26

81.25%

23

1990-1993

5

13

72.22%

23

1994-1997

2

5

71.43%

23

1998-2002

3

12

80.00%

23

2003-2006

3

9

75.00%

24

1990-1993

4

7

63.64%

24

1994-1997

6

1

14.29%

24

1998-2002

6

6

50.00%

24

2003-2006

7

5

41.67%

25+

1990-1993

6

1

14.29%

25+

1994-1997

3

2

40.00%

25+

1998-2002

8

4

33.33%

25+

2003-2006

6

1

14.29%

It appears that Baseball America was better at identifying
top talent aged 20-22 from 1990-1997 than it was in 1998-2006 but still ranked
80% of successful position rookies in that age group. While Baseball America
accurately identified a large percentage of top offensive talent that entered
the majors from ages 20-23, they were less able to identify top offensive
talent that first entered the majors at 24 or older.Many of the successful ranked rookies who
entered the majors for the first time at 24 were ranked from 51-100.

Another point worth covering is whether these trends remain
true for both prospects that went to the majors after high school and those
that went to the majors after attending college. This data can be found in a database created by Sean Lehman for all
players that make it to the majors. Players that went to either a
Junior College or Community College were excluded from this analysis because
there were very few of them and the drafting rules for players at either of
these are different than those drafted out of high school or a four year
college.

This table shows the success rates of ranked offensive
prospects based on whether they went to college.

Age Group

College

Success Rate

Number Successful

20-22

No

40.24%

68

20-22

Yes

59.26%

16

23

No

28.57%

16

23

Yes

47.50%

19

24

No

9.09%

2

24

Yes

37.78%

17

25+

No

15.00%

3

25+

Yes

31.25%

5

The majority of successful
ranked prospects are those that go to high school and make it to the majors
before they are 23 years old. Nearly all high school ranked offensive prospects
that succeed make it to the majors before they are 24 years old. Younger high school ranked offensive prospects have a better chance of
success than older high school ranked offensive prospects.

While fewer college prospects between ages 20-22 make it to
the majors than high school prospects aged 20-22
those who do have higher success rates than the high school prospects. Like
high school prospects, younger college offensive prospects have better success
rates than older college offensive prospects.Unlike high school prospects, ranked college position prospects have
good chances of succeeding no matter when they reach the majors.

This table shows the success rates of unranked offensive
prospects based on whether they went to college or not.

Age Group

College

Success Rate

Number Successful

20-22

No

13.48%

12

20-22

Yes

21.43%

3

23

No

5.68%

5

23

Yes

13.95%

6

24

No

9.89%

9

24

Yes

13.48%

12

25+

No

4.67%

7

25+

Yes

6.87%

16

Unranked college prospects are more
likely to be successful than unranked high school prospects. The earlier that
both high school and college unranked prospects make it to the majors, the
higher the chances that they will be successful.

Unranked high school offensive
prospects are very unlikely to be successful if they don’t make it to the
majors when they are 22 or younger. Unranked college prospects are most likely to be successful
if they can make it to the majors when they are 22 or younger. Many successful college
prospects were successful despite not reaching the majors until they were 24.

The above shows the success rate of offensive
prospects based on age. Now, we can do the same analysis for pitching prospects.
Here is the success rates for ranked pitching prospects:

Age Group

Year Group

Success Percent

Successful Prospects

20-22

1990-1993

20.00%

7

20-22

1994-1997

21.43%

9

20-22

1998-2002

44.26%

27

20-22

2003-2006

38.30%

18

23

1990-1993

28.57%

6

23

1994-1997

27.78%

5

23

1998-2002

34.62%

9

23

2003-2006

20.00%

4

24

1990-1993

16.67%

1

24

1994-1997

25.00%

2

24

1998-2002

10.00%

1

24

2003-2006

9.09%

1

25+

1990-1993

25.00%

2

25+

1994-1997

6.67%

1

25+

1998-2002

25.00%

2

25+

2003-2006

22.22%

2

From 1998-2006 most successful
ranked pitching prospects made it to the majors by 22. The ones who did so had a good shot at being successful. Very few ranked pitching prospects succeeded if they didn’t make
it to the majors by the time they were 23. While it looks like pitching
prospects older than 25 succeeded at high rates, it is important to realize that
those numbers are inflated by “prospects” that go straight to the majors such as Jose Contreras and Rolando Arrojo as well as low sample
size.

The next table shows the success rates of unranked pitching
prospects:

Age Group

Year Group

Success Rate

Successful Prospects

20-22

1990-1993

22.50%

9

20-22

1994-1997

13.79%

4

20-22

1998-2002

6.00%

3

20-22

2003-2006

2.08%

1

23

1990-1993

2.63%

1

23

1994-1997

7.32%

3

23

1998-2002

11.11%

6

23

2003-2006

5.17%

3

24

1990-1993

10.17%

6

24

1994-1997

10.20%

5

24

1998-2002

5.00%

4

24

2003-2006

6.38%

3

25+

1990-1993

2.13%

3

25+

1994-1997

1.65%

2

25+

1998-2002

3.55%

5

25+

2003-2006

2.46%

3

From 1998-2006, Baseball America did a very good job identifying the top pitching
prospects between ages 20-22. As a result, the vast majority of unranked
pitching prospects failed regardless of age.If this trend continues than very few unranked
pitching prospects will be successful.

The following tables show the number of successful pitching
prospects by their Baseball America rank or lack thereof.

Age Group

Year Group

1-10

11-20

21-30

31-50

51-100

Not

20-22

1990-1993

3

2

1

0

1

9

20-22

1994-1997

1

2

2

2

2

4

20-22

1998-2002

7

4

2

4

10

3

20-22

2003-2006

5

3

4

3

3

1

23

1990-1993

0

0

2

1

3

1

23

1994-1997

1

1

0

2

1

3

23

1998-2002

1

1

1

2

4

6

23

2003-2006

0

1

1

1

1

3

24

1990-1993

0

0

0

0

1

6

24

1994-1997

0

1

0

0

1

5

24

1998-2002

1

0

0

0

0

4

24

2003-2006

0

0

0

1

0

3

25+

1990-1993

0

0

0

1

1

3

25+

1994-1997

0

0

0

0

1

2

25+

1998-2002

0

0

0

2

0

5

25+

2003-2006

1

1

0

0

1

2

This table compares the number of successful top hundred prospects to non top hundred prospects.

Age Group

Year Group

Not Top Hundred

Top Hundred

Success Rate

20-22

1990-1993

9

7

43.75%

20-22

1994-1997

4

9

69.23%

20-22

1998-2002

3

27

90.00%

20-22

2003-2006

1

18

94.74%

23

1990-1993

1

6

85.71%

23

1994-1997

3

5

62.50%

23

1998-2002

6

9

60.00%

23

2003-2006

3

4

57.14%

24

1990-1993

6

1

14.29%

24

1994-1997

5

2

28.57%

24

1998-2002

4

1

20.00%

24

2003-2006

3

1

25.00%

25+

1990-1993

3

2

40.00%

25+

1994-1997

2

1

33.33%

25+

1998-2002

5

2

28.57%

25+

2003-2006

3

2

40.00%

Baseball America is really successful at projecting top talent from 20-22. Baseball America has historically had very little success projecting talent that's 24 or older.

We saw earlier that from 1998-2006 that
unranked pitching prospects have rarely been successful. The following table
can show us whether these trends remain true for prospects that went to the
majors after high school and those that went to the majors after college.

Age Group

College

Success Rate

Total Successful

20-22

No

0.00%

0

20-22

Yes

5.26%

1

23

No

8.70%

6

23

Yes

8.10%

3

24

No

3.22%

2

24

Yes

7.40%

4

25+

No

3.54%

4

25+

Yes

3.01%

4

Very few unranked pitching prospects were successful from 1998-2006 regardless of whether they went to college or high school. There are roughly three successful unranked pitching prospects per year from 1998-2006. This table describing the performance of ranked pitching prospects based on whether they went to high school or college from 1998-2006 is more interesting.

Age Group

Year Group

College

Success Rate

Total Success

20-22

1998-2002

No

44.23%

23

20-22

2003-2006

No

42.42%

14

20-22

1998-2002

Yes

50.00%

4

20-22

2003-2006

Yes

30.00%

3

23

1998-2002

No

31.58%

6

23

2003-2006

No

14.29%

1

23

1998-2002

Yes

40.00%

2

23

2003-2006

Yes

27.27%

3

24

1998-2002

No

16.67%

1

24

2003-2006

No

0.00%

0

24

1998-2002

Yes

0.00%

0

24

2003-2006

Yes

20.00%

1

25+

1998-2002

No

28.57%

2

25+

2003-2006

No

33.33%

1

25+

1998-2002

Yes

0.00%

0

25+

2003-2006

Yes

16.67%

1

A plurality of successful pitchers go to high school and make it to the majors by 22. However, college pitchers that make it to the majors by 22 have similar success rates. Also college pitchers that reach the majors by 23 are more likely to be successful than high school pitchers that reach the majors by 23. Very few ranked pitchers older than 24 are successful.

To sum up, offensive prospects that went to college had a higher success rate than offensive prospects that went to high school regardless of whether they were ranked. However, the majority of successful offensive rookies did not go to college. The majority of successful pitching prospects also did not go to college and success rates for high school and college rookies were similar.

Baseball America was able to determine the best talent that reaches the majors before 23 with the exception of pitching prospects from 1990-1997. It successfully ranked 80% of successful offensive talent and 90% of successful pitching talent that made it to the majors before 23. Baseball America was much less successful at determining talent that makes it to the majors after 23.

Unranked offensive talent that made it to the majors by 22 had a surprisingly high success rate regardless of whether they went to college or not. So did unranked offensive talent that made it to the majors by 24 that went to college. This indicates that Baseball America could improve the accuracy of its projections by ranking more of these players.

Very few pitchers that made it to the majors that were 24 or older were successful regardless of whether they went to college or not. Baseball America was able to predict only one successful pitcher in this age bracket roughly every three years from 1998-2006.

The majority of successful prospects entered the
majors by 22. This indicates that age is more than just a number. The earlier a player reaches the
majors the better his chances of success. Age has a definite impact on prospect success rates.

Contributors

Jon Shepherd - Founder/Editor@CamdenDepotStarted Camden Depot in the summer of 2007. By day, a toxicologist and by night a baseball analyst. His work is largely located on this site, but may pop up over at places like ESPN or Baseball Prospectus.

Matt Kremnitzer - Assistant Editor@mattkremnitzerMatt joined Camden Depot in early 2013. His work has been featured on ESPN SweetSpot and MASNsports.com.

Patrick Dougherty - Writer@pjd0014Patrick joined Camden Depot in the fall of 2015, following two years writing for Baltimore Sports & Life. He is interested in data analysis and forecasting, and cultivates those skills with analysis aimed at improving the performance of the Orioles (should they ever listen).

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Joe Reisel - WriterJoe has followed the Norfolk Tides now for 20 seasons. He currently serves as a Tides GameDay datacaster for milb.com and as a scorer for Baseball Info Solutions (BIS). He is computer programmer/analyst by day.

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